In recent years, various types of photographed image display devices using a semiconductor photodetector such as a Charge Coupled Device (CCD) for converting light into electrical signals have rapidly become widespread. Such photographed image display devices include digital cameras, and mobile communications terminals such as mobile telephones and Personal Digital Assistants (PDAs) equipped with a digital camera.
FIG. 9 is a functional block diagram illustrating an example construction of a conventional photographed image display device 100.
The photographed image display device 100 is constituted by a camera unit 110, a frame memory 120, a liquid crystal display (LCD) module 130, a CPU 140, an operation unit 150, a storage unit 160, and an Application Specific Integrated Circuit (ASIC) 170.
The camera unit 110 photographs an object, and sequentially outputs image data obtained by the photographing (hereinafter referred to as photographed image data) to the ASIC 170.
Here, “to photograph an object” represents a process of forming an image of the object on the light-receiving surface of a semiconductor photodetector through a lens of a camera and converting the formed image into image data.
The frame memory 120 temporarily stores photographed image data transferred from the ASIC 170.
The LCD module 130 includes a graphic Random Access Memory (GRAM) 131, and an LCD 132. Photographed image data input to the LCD module 130 from the ASIC 170 is displayed on the LCD 132.
The GRAM 131 temporarily stores photographed image data input from the ASIC 170.
The LCD 132 displays the photographed image data.
The CPU 140 receives a user's instruction input through the operation unit 150, and issues an instruction corresponding to the user's instruction to an appropriate constituent. For example, when receiving a photographing start instruction from a user, the CPU 140 instructs the ASIC 170 to execute a photographing operation. When receiving a photographed image storage instruction, the CPU 140 reads the photographed image data stored in the frame memory 120, and stores the photographed image data in the storage unit 160.
The operation unit 150 generates a corresponding instruction signal, when receiving the user's instruction, and outputs the generated instruction signal to the CPU 140.
The storage unit 160 stores photographed image data input by the CPU 140.
The ASIC 170 controls the photographing operation in the following manner. When the CPU 140 instructs the ASIC 170 to execute the photographing operation, the ASIC 170 receives photographed image data output from the camera unit 110. The ASIC 170 performs image processing (e.g. color correction) on the photographed image data, and then transfers the photographed image data to the frame memory 120. Furthermore, the ASIC 170 reads the photographed image data from the frame memory 120 to output the photographed image data to the LCD module 130.
Thus, the user of this photographed image display device 100 can photograph an image of a desired object, and store the photographed image.
As described above, the conventional photographed image display device 100 requires the frame memory 120 as a buffer memory, to enable photographed image data to be retrieved as needed in response to the photographed image storage instruction from the user.